title: Effect of underwater treadmill exercise on postural sway in horses with experimentally induced carpal joint osteoarthritis.
abstract: OBJECTIVE
  To evaluate the effect of underwater treadmill exercise on static postural sway in horses with experimentally induced carpal joint osteoarthritis under various stance conditions.
  
  
  METHODS
  16 horses.
  
  
  METHODS
  On day 0, osteoarthritis was induced arthroscopically in 1 randomly selected middle carpal joint of each horse. Beginning on day 15, horses were assigned to either underwater or overground (without water) treadmill exercise at the same speed, frequency, and duration. Two serial force platforms were used to collect postural sway data from each horse on study days -7, 14, 42, and 70. Horses were made to stand stationary on the force platforms under 3 stance conditions: normal square stance, base-narrow placement of the thoracic limbs, and removal of visual cues (blindfolded) during a normal square stance. The mean of 3 consecutive, 10-second trials in each condition was calculated and used for analysis.
  
  
  RESULTS
  Displacement of the center of pressure differed significantly depending on the stance condition. Among horses exercised on the underwater treadmill, postural stability in both the base-narrow and blindfolded stance conditions improved, compared with findings for horses exercised on the overground treadmill. Horses exercised on the overground treadmill were only successful at maintaining a stable center of pressure during the normal square stance position.
  
  
  CONCLUSIONS
  Variations in stance position had profound effects on the mechanics of standing balance in horses with experimentally induced carpal joint osteoarthritis. Underwater treadmill exercise significantly improved the horses' postural stability, which is fundamental in providing evidence-based support for equine aquatic exercise.
authors.affiliation: Equine Orthopaedic Research Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA. Melissa.King@Colostate.edu
authors.forename: Melissa R
authors.initials: MR
authors.lastname: King
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Haussler
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Kawcak
authors.forename: C Wayne
authors.initials: CW
authors.lastname: McIlwraith
authors.forename: Raoul F
authors.initials: RF
authors.lastname: Reiser Ii
mesh_terms: D000818:Animals; D050824:Carpal Joints / Q000187:drug effects / Q000473:pathology*; D005080:Exercise Test / Q000662:veterinary*; D006734:Horse Diseases / Q000139:chemically induced* / Q000473:pathology; D006736:Horses; D007794:Lameness, Animal; D010003:Osteoarthritis / Q000139:chemically induced / Q000662:veterinary*; D010805:Physical Conditioning, Animal / Q000502:physiology*